My car arrived UK in June, as was fitted with the 450c dipstick, and according to the dealer, had the latest software and sensor fitted - and 5 months and 6000 miles later, the oil level is still OK.
I couldn't tell you if it's going into regen too much as I've never noticed a regen happening, but I've never even really looked out for it. It sounds like the kind of thing you have to be looking/ listening for.
I'd did a 50 miles drive home yesterday trying to be economical, 20 miles along a fairly hilly A road through the Cotswolds and then 30 miles on the M5, and got an average for that trip of 45. What I saw in the instantaneous mpg read out tied in with what others have seen, with the figure fluctuating a lot, even when relatively flat. Having said that, a hill kills the consumption, and increasing the speed on the motorway to my typical cruising speed causes a noticeable drop.
I'm not too worried about my overall consumption of 37, which may be possibly down to driving style and/or pattern, but will mention it when next at the dealers (which hopefully will not be until first service in about April/May). Until then I will probably reset the average consumption figure more often to get a better picture of what happens when, as yesterday was the first reset since new.